Understanding SPF, DKIM, and DMARC: A Simple Guide

This is a great guide but from my experience, even if you configure it 100% correctly, email services like Gmail may still classify your emails as spam for no apparent reason while not being on any IP or domain blacklist. I tried for hundreds of hours to get around it with no avail, and my emails to Gmail always went to spam unless it was a response to an email from a Gmail address. Had to go back to a 3rd party hosted service (iCloud) because of it.

Came here to say this, plus add a little personal insight to the future of email.

I've run 5 or 6 different mail servers over the past 10 years. Originally before O365 I was an exchange admin, then postfix, iRed, mailcow, mail gun, you name it. Hosted on every cloud provider, even in our colo with part of a private /24 allocation with good reputation (built since 1997, gawdamn). Every sort of header combination, tls setup, and no blacklists. Always 100% alignment, including strict rejection policy (best results even over quarantine).

Does not matter, if you're sending from custom domain not handled through a big name, expect the spam box with Gmail. Yahoo and Outlook are fine, but Gmail is the bane.

I've spent maybe 100 hours of my own over this last year and know what I realized? Nobody cares about email anymore, except for automated account management stuff (login, PW reset). Businesses pay the $3 /mo / seat for fastmail and don't think twice.

But the current trend is toward social chat (discord or Whatsapp) and most the people who own an iPhone just use their apple ID email for everything.

Although I am a fervent supporter of open protocols and believe email (with pgp signing) is an awesome long form communication format... Face it, it's going the way of the fax machine.